Yep no argument there, that the tests are done and qualified on those targe= ted hosts. Maybe I ought to put a bug in someones ear about looking closer= at the SPI mode on these devices. That's a whole different group so I dou= bt it would go anywhere :-) -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of= James Cameron Sent: Monday, May 18, 2015 2:43 PM To: Microcontroller discussion list - Public. Subject: Re: [PIC] SDHC read problem On Mon, May 18, 2015 at 04:39:50PM +0000, Harrison Cooper wrote: > James...aren't camera's and cell phones, where the SD cards are > targeted use for, embedded devices? So the firmware is actually > tested against those more so than an OS. The software in cameras and telephones tends to be somewhat homogenous, and= closer in complexity to an OS than to a PIC with SPI pins. Product engine= ering for a mass production device checks for compatibility across a wide r= ange of SD cards. Smaller runs find it hard to justify that work. It's no= n-recurring engineering. Estimating the number of formal compatibility tests done between SD cards a= nd their hosts; yes, the majority of the tests are done against embedded de= vices, but that's because there are problems in that space. Estimating the number of informal compatibility tests, where a customer buy= s an after-market SD card and attaches it to a host; the majority of such t= ests _so far_ have been done against an OS; Windows, Linux/Android, Mac OS = X, iOS. As the tests aren't rolled up anywhere, the number of tests isn't a particu= larly useful quantity. Sorry about that. Perhaps it is the maintenance longevity of the OS kernel code that has led = to stability and reliability of the interface. Some embedded devices are h= ere today, gone tomorrow. -- James Cameron http://quozl.linux.org.au/ -- http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/chang= e your membership options at http://mailman.mit.edu/mailman/listinfo/piclis= t ________________________________ PLEASE NOTE: The information contained in this electronic mail message is i= ntended only for the use of the designated recipient(s) named above. If the= reader of this message is not the intended recipient, you are hereby notif= ied that you have received this message in error and that any review, disse= mination, distribution, or copying of this message is strictly prohibited. = If you have received this communication in error, please notify the sender = by telephone or e-mail (as shown above) immediately and destroy any and all= copies of this message in your possession (whether hard copies or electron= ically stored copies). --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .